Typical multi-layered vacuum super insulated cryogenic tanks utilize a pair of cylindrical inner and outer tanks that are arranged concentrically with the inner tank residing in an interior of the outer tank. There are multiple radiant heat shields, approximately 30-80, coiled around the inner tank between the inner and outer tanks. A high vacuum exists between the inner and outer tanks to further prevent heat transfer. This type of thermal insulation is called a multi-layered vacuum super insulation. These storage tanks are capable of storing fluids at cryogenic temperatures.
The inner tank is positioned within the outer tank so that the inner tank does not contact the outer tank and so that thermal conduction paths between the inner and outer tanks are minimized. In one type of cryogenic storage tank, the inner tank is suspended within a central segment of the outer tank by four rigid tensile rods or sticks at each end that extend radially to central segment of the outer tank. The rods are individually preloaded to suspend the inner tank within the outer tank. The use of four rods on each end statically overconstrains the inner tank thereby resulting in an undefined stress distribution due to the preload and when the inner tank is loaded with a fluid. The extra rods also provide extra parasitic heat leaks. Furthermore, the use of the rods imparts localized stress concentrations on the central segment of the outer tank due to the suspending of the inner tank therein. The localized stress concentrations can deform portions of the central segment and impede the attachment of the end caps of the outer tank to the central segment.
Thus, it would be advantageous suspend the inner tank within the outer tank in a manner that does not impede the attachment of the end caps. It would also be advantageous if the suspending of the inner tank within the outer tank facilitated assembly of the storage tank.